I agree the variety in humans means we have a small percentage who differ.
What I'm objecting to is the normalization of abberant behaviour as "oh that's just something we do." It's not something most of us do.
When someone comes along like Jimmy Saville people don't say oh, large scale pedophilia is just human nature.
We quite rightly view it as abberant and our focus is on seeking to put a stop to it. The same thing should happen with things like genocide and ethnic cleansing.